Therefore, the results of the new study support the idea that primitive life could potentially have evolved on Ganymede. This is because places where water and rock interact are important for the development of life. For example, some theories suggest that life arose on our planet within hot, bubbling seafloor vents. Before the new study, Ganymede's rocky seafloor was believed to be coated with ice--not liquid. This would have presented a problem for the evolution of living tidbits. The "Dagwood sandwich" findings, however, indicate something else entirely--the first layer on top of Ganymede's rocky core might be made up of precious, life-sustaining salty water.

The more recently imaged plume erupts to a height of 62 miles above Europa's surface, while the one seen in 2014 was estimated to rise almost half as high at 30 miles above its surface. Both erupting plumes are located in an unusually warm region of this icy small world. This relatively toasty area shows some strange features that appear to be cracks in the moon's shell of ice, that were first observed back in the late 1990s by NASA's Galileo spacecraft. Planetary scientists propose that, like Enceladus, this could be a sign of water erupting from a sloshing global ocean of liquid water, swirling around in the moon's interior, that is hidden beneath its crust of surface ice.

Ganymede is the largest moon in our Solar System. Indeed, its impressive diameter of nearly 3,280 miles makes it almost as big as Mars! Astronomers have known since the 1990s that this frigidly cold moon, that circles around the gas-giant planet Jupiter, contains a hidden salty subsurface ocean of liquid water, sloshing around deep beneath its secretive shell of ice. However, in May 2014, planetary scientists announced that the situation may be somewhat more complicated--Ganymede's ocean might be organized like a multi-tiered sandwich, with ice and oceans stacked up in several layers, according to new NASA-funded research that models this enormous moon's composition.